The present disclosure relates generally to downhole tools and, more particularly, to an expandable bullnose assembly.
During the construction, completion, and/or intervention of wells in the oil and gas industry, well operators often use bullnose assemblies to tag, deflect, jet or otherwise physically interact with various downhole tools within a wellbore. The ability to use a particular bullnose assembly is limited by its outer diameter, which must be able to pass through restrictions in the wellbore or completion above the intended engagement.
In some cases, the bullnose assembly is used to direct a tool string to a desired location within a wellbore. For instance, some wellbores include one or more lateral wellbores that extend at an angle from a parent or main wellbore. Such wellbores are commonly referred to as multilateral wellbores. Various devices and downhole tools can be installed in a multilateral wellbore in order to direct a tool string toward a particular lateral wellbore. A deflector or whipstock, for example, is a device that can be positioned in the main wellbore at a junction within the main wellbore and configured to direct a bullnose assembly conveyed downhole toward a lateral wellbore that extends from the main wellbore at the junction. Depending on various parameters of the bullnose assembly, some deflectors also allow the bullnose assembly to remain within the main wellbore and otherwise bypass the junction without being directed into the lateral wellbore.
Accurately directing the bullnose assembly into the main wellbore or the lateral wellbore can often be a difficult undertaking. For instance, accurate selection between wellbores commonly requires that both the deflector and the bullnose assembly be correctly oriented within the well and otherwise requires assistance from known gravitational forces. Moreover, conventional bullnose assemblies are typically only able to enter a lateral wellbore at a junction where the design parameters of the deflector correspond to the design parameters of the bullnose assembly. In order to enter another lateral wellbore at a junction having a differently designed deflector, the bullnose assembly must be returned to the surface and replaced with a bullnose assembly exhibiting design parameters corresponding to the differently designed deflector. As can be appreciated, this process can be time consuming and costly.